An Indonesian volcano near an ancient volcano that once nearly destroyed humankind is getting ready to erupt. At the moment, it’s throwing smoke high into the sky.

Sinabung volcano in Northern Sumatra, Indonesia, is only 35 kilometers from the Toba volcano whose super-eruption, according to scientists, put mankind on the brink of extinction almost 70,000 years ago by causing a “nuclear winter,” which could have lasted several years

A 1.5-mile-high column of searing gas and ash over Sinabung is a sign of an ongoing eruption. The smoke over the crater could spell disaster.

“The growing size of the lava dome is very unstable,” said government volcanologist Surono. That means there is a threat of a more powerful eruption, which could be accompanied by pyroclastic flows. This is the type of volcanic events which destroyed ancient Pompeii. The scientist urged villagers to stay out of a four-mile zone southeast of the crater.

On Wednesday, authorities registered over 50 separate eruptions. Last week, more than 2,700 people were evacuated from local villages. The government says there is no danger to people from non-evacuated areas at the moment.

Sinabung has been erupting from time to time since 2010, after more than 400 years of being dormant. In 2014, at least 17 people were killed by Sinabung eruptions.